package cn.tedu.sp06.fb;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

/**
 * 定义订单服务的降级类, 需要是实现FallbackProvider接口.
 * 并交给spring管理
 */
@Component
public class OrderFB implements FallbackProvider {

    /**
     * @return 返回一个service-id， 表示当前降级类是针对哪个后台服务的降级类
     *  --- order-service :表示只对商品服务降级
     *  --- * :对所有服务都应用这个降级类
     *  --- null :等同于 *
     */
    @Override
    public String getRoute() {
        return "order-service";
    }

    /**
     * 发回给客户端的降级响应
     */
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {

            }

            @Override
            public InputStream getBody() throws IOException {
                String json = JsonResult.err().code(500).msg("调用后台服务出错").toString();

                return new ByteArrayInputStream(json.getBytes(StandardCharsets.UTF_8));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders headers = new HttpHeaders();
                headers.add("Content-Type", "application/json;charset=UTF-8");
                return headers;
            }
        };
    }
}
